//
//  ViewController.m
//  CoreData67
//
//  Created by dllo on 15/11/20.
//  Copyright (c) 2015年 贺艳超. All rights reserved.
//

#import "ViewController.h"
#import "Student.h"
#import "CoreDataManager.h"



@interface ViewController ()
@property(nonatomic, retain) CoreDataManager *manager;


@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    
    // 数据管理器 单例方法初始化
    self.manager = [CoreDataManager defaults];
    
    NSLog(@"++==========%@", [self.manager applicationDocumentsDirectory]);
    
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

// CoreData的添加方法
- (IBAction)add:(UIButton *)sender {
    
    // 创建实体描述
    // 参数1:描述的实体
    // 参数2: 数据管理器
    NSEntityDescription *entity = [NSEntityDescription entityForName:@"Student" inManagedObjectContext:self.manager.managedObjectContext];
    
    // 创建实体
    // 参数1: 实体描述
    // 参数2: 数据管理器
    Student * stu = [[Student alloc] initWithEntity:entity insertIntoManagedObjectContext:self.manager.managedObjectContext];
    
    stu.name = @"成精";
    stu.age = @1000;
    stu.sex = @"?";
    stu.hobby = @"女";
    stu.number = @67;
    
    [self.manager saveContext];
    
    
}

// 查找

- (IBAction)select:(UIButton *)sender {
    
    // 获取查询数据的请求, 相当于数据库的查询语句
    NSFetchRequest *request = [[NSFetchRequest alloc] initWithEntityName:@"Student"];
    
    // 添加一个约束 谓词
    NSPredicate * predicate = [NSPredicate predicateWithFormat:[NSString stringWithFormat:@"%@ == %@", @"name", @"%@"], @"成精"];
    // 给请求添加约束
    request.predicate = predicate;
    
    // 通过某个key给数组排序
    NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"name" ascending:YES];
    
    [request setSortDescriptors:[NSArray arrayWithObjects:sortDescriptor, nil]];
    
    NSError *error;
   
    NSArray *array = [self.manager.managedObjectContext executeFetchRequest:request error:&error];
    
    NSLog(@"%ld", array.count);
    
    
    
}
// 修改
- (IBAction)update:(UIButton *)sender {
    
    // 获取查询数据的请求, 相当于数据库的查询语句
    NSFetchRequest *request = [[NSFetchRequest alloc] initWithEntityName:@"Student"];
    
    // 添加一个约束 谓词
    NSPredicate * predicate = [NSPredicate predicateWithFormat:[NSString stringWithFormat:@"%@ == %@", @"name", @"%@"], @"成精"];
    // 给请求添加约束
    request.predicate = predicate;
    
    // 通过某个key给数组排序
    NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"name" ascending:YES];
    
    [request setSortDescriptors:[NSArray arrayWithObjects:sortDescriptor, nil]];
    
    NSError *error;
    
    NSArray *array = [self.manager.managedObjectContext executeFetchRequest:request error:&error];
    
    Student *stu = [array lastObject];
    stu.sex = @"幺么觉着";
    
    [self.manager saveContext];
    
}
#pragma mark fetch 快捷键
// 删除
- (IBAction)delete:(UIButton *)sender {
    
    NSFetchRequest *request = [[NSFetchRequest alloc] initWithEntityName:@"Student"];
    
    NSPredicate *predicate = [NSPredicate predicateWithFormat:[NSString stringWithFormat:@"%@ == %@", @"sex", @"%@"], @"?"];
    
    request.predicate = predicate;
    
    NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc ] initWithKey:@"name" ascending:YES];
    [request setSortDescriptors:[NSArray arrayWithObjects:sortDescriptor, nil]];
    NSError *error;
    
    
    NSArray *array = [self.manager.managedObjectContext executeFetchRequest:request error:&error];
    
    
    for (Student *stu in array) {
        
        [self.manager.managedObjectContext deleteObject:stu];
        
    }
    [self.manager saveContext];
    
}






@end
